Coat of Arms for Von STEINER family in Weinsberg Germany

I was told by grandmother that her great great grandfather was a Baron named Von Steiner. According to her his son married a girl who was not of nobility and they lost the Von and were just named Steiner after that. Is there any way that I can research that. According to my mother remains of the Stammburg are along the Rhine River. Any help on this would be great.This may go back too far in time because my grandmother was born in 1893. Don't know if records area available that far back.
Thank you,
ChrisW.

Hi Renate{again}
I guess I am really making things difficult for you when you are trying to help. There are no documents that I am aware of,it is what my grandmother told my mother about her family heritage. The {von} Steiners never left Germany as far as I know, although my grandmothers half brothers came to the states with their fathers last name , not Steiner. My mother told me this story and my Grandmother who is a Steiner stayed in Germany until the mid or late 60's. Don't know if this helps.